Pumps



R. C. LEFF Nov. 9, 1965 PUMPS Filed Dec. 27, 1963 7 6 4 4% I- I 60 m d aa n U 7 2 4 5 8% 3 O 2 9 2 a FIG-5 4 a 4 a W a O O 3 O o 3 8 4 w 00 0 0oQ0 R @s mw BE m VL 0 WC. T T T A R E B 0 RM an a Z 3 0 Ta 1 a v6 9 8 I Ia 9% a United States Patent Ohio Filed Dec. 27, 1963, Ser. No. 333,965 4Claims. (Cl. 103-111) This invention relates to pumps.

The invention has special relation to sump pumps and the like wherein animpeller operates at the end of its drive shaft within a pumpingchamber. It is important for optimum efficiency with such pumps that theimpeller be held in relatively closely spaced relation with the wall ofthe pumping chamber wherein the suction inlet is located, particularlyin the case of an open faced vaned impeller. At the same time, it isdesirable that pumps of this type be capable of production at relativelylow unit cost, with relatively wide manufacturing tolerances, but thatthey be capable of a long satisfactory operating life under evenrelatively severe service conditions.

It is a primary object of the present invention to provide a pump of thegeneral type outlined above wherein the impeller and associated partsare of novel structure making possible quick and easy adjustment of theimpeller on its drive shaft at the time of final assembly, and alsoassuring that the impeller will be retained in its accuratelyestablished position 'during operation of the pump.

It is a particular object of the invention to provide a pumpconstruction as outlined in the preceding paragraph wherein the impelleris infinitely adjustable within a sufiiciently large range to compensatefor even relatively wide tolerances in the initial manufacture of itscomponent parts, and which is accordingly adaptable to mass productionat relatively low unit cost.

It is also an object of the invention to provide a pump as outlinedabove wherein the impeller may be adjusted in the field with the samecase as during initial assembly of the pump.

Other objects and advantages of the invention will be apparent from thefollowing description, the accompanying drawings, and the appendedclaims.

In the drawings:

FIG. 1 is a view partly in section and partly in elevation of a pumpconstructed in accordance with the present invention;

FIG. 2 is a view in bottom plan of the pump of FIG. 1 with the baseremoved;

P16. 3 is an enlarged fragmentary view in vertical section of a portionof the structure of FIG. 1, showing in detail the construction of thedriving shaft and its seal;

FIG. 4 is a fragmentary view in vertical section showing details of theadjustment of the impeller relative to the drive shaft; and

FIG. 5 is a sectional view on the line 55 of FIG. 3 but on a smallerscale than FIG. 3.

Referring to the drawing, which illustrates a preferred embodiment ofthe present invention, FIG. 1 shows a representative form of a pumpwhich includes a motor section generally designated and a pump sectiongenerally designated 12. A motor 14 is positioned within an outer shell16. On the upper end of the shell 16 is -an upper motor housing 18, andthe shell 16 extends at its lower end into a lower housing 20. The upperhousing 18, the shell 16 Patented Nov. 9, 1965 and the lower housing 20are held together in substantially sealed relationship by a plurality ofthrough bolts such as the bolt 22. The upper housing 18, the outer shell16 and the lower housing 20 alternatively may be joined together by useof an epoxy cement or other suitable means well known in the art.

The motor 14 includes a stator 24 supported by the shell 16 and rotor 25which is carried by the shaft 26, the upper end of the shaft beingsupported in the upper housing 18 by a bearing 27 and a retainer 28. Thelower end of the shaft 26 carries an impeller 30 provided with aplurality of impeller blades 32, the impeller 30 being secured to theshaft by a lock screw 33 as more fully described hereinafter. The lowerend and the intermediate portion of the shaft 26 are supported in abearing assembly 34, and intermediate the bearing assembly 34 andimpeller 30 is a rotary seal assembly 35.

Electric current is supplied to a switch assembly 41 by a conduit 42 andis supplied from the switch assembly 41 to the motor 14 by a conduit 43.The switch assembly 41 includes a diaphragm or other type of switchwhich is controlled by pressure and/ or by depth of liquid surroundingthe pump to operate the motor. Any suitable switch such as a pressureswitch or float switch may be utilized to energize the motor 14 inresponse to the presence of liquid above any predetermined level.

In the bottom end of the pump housing 20 is the impeller chamber orvolute chamber 44, which as shown in FIG. 2 is in the form of aneccentric spiral and terminates in an outlet chamber 45. The housing 20is threaded at 46 above the chamber 45 to receive the discharge pipe 47.The bottom wall 48 of the chambers 44 and 45 is formed by a portion ofthe base 50 which supports the pump, and which is provided with multipleperforations 51 around its exterior to admit water for entry to thepumping chamber 44 through the impeller inlet opening 52 in the wall 48.A check valve 55 is provided in the housing 20 above the chamber 45 toprevent return of liquid from discharge pipe 47 to the chambers 45 and44 when the pump is shut off.

Referring now especially to FIGS. 1 and 4, the lower end of the shaft 26is grooved as at 61, and a spline 62 formed in the internal bore of theimpeller 31 cooperates with the groove 61 to secure the impeller 30against rotation on shaft 26. Means are provided for effecting accurateadjustment of the impeller 31 up and down on the shaft 26. Referringparticularly to FIG. 4, the lower end of shaft 26 is formed with atapped bore 63 for the screw 33, which screw is formed to be elfectivelyself-locking, as illustrated by the provision therein of a slot 65 intowhich there is inserted a wedge 66 of nylon or other resilient meansestablishing a self-locking relation with bore 63. Between the head ofthe screw 33 and the lower end surface 68 of the impeller 31 is inserteda washer 69.

FIG. 4 shows the impeller 30 in an intermediate position between itsuppermost position relative to the shaft 26 and its lowermost positionrelative thereto. Thus screw 33 may be threaded further into the bore 63to move the impeller 30 upward on shaft 26, and similarly if screw 33 isbacked off in bore 63, the impeller is free to move down the shaft.Resilient means are provided in accordance with the invention formaintaining the impeller in firmly seated position on the washer 69 inall its adjusted positions as now described.

Referring particularly to FIG. 3, the bearing assembly 34 is arranged toform a thrust bearing positively limiting downward movement of the shaft26. It includes an outer race 70 which is seated on the annular shoulder71 at the bottom of a counterbore 72 in the lower housing 20. The'balance of the bearing comprises the usual balls 74 and inner race 75.A snap ring 77 is received in a slot 78 of the shaft 26 and forms ashoulder which seats on the inner race 75 to limit downward movement ofthe shaft with respect to housing 20.

The rotary seal assembly 35 includes resilient means continuously urgingthe impeller 30 downwardly against the washer 69. Referring to FIG. 3,the lower housing 20 is provided on its under side with a counterbore 80in which the stationary seal ring 81 of ceramic or like material ismounted by means of a suitable gasket 82 of neoprene or like material.The rotating seal ring 83 is secured to the shaft 26 by a neoprenediaphragm 85, a metal shell 86, and a neoprene friction seal ring 88which seals to but is axially movable along shaft 26 and engages theupper end face 89 of the impeller 30. The diaphragm 85 is clamped by arelatively heavy coil spring 90 against the rotating seal ring 83 andthe opposed annular flange portion of the shell 86, and the shell 86includes an inner annular shoulder 91 which seats on ring 88.

The axial thrust of the spring 90 not only maintains the seal members 81and 83 in running sealing engagement, but it continuously urges the sealring 88 axially against the impeller end face 89 and thereby urges theimpeller downwardly along shaft 26 into firmly seated relation on thewasher 69, and this spring force is supplemented by the downwardhydraulic force which is developed by the impeller in operation. Sincethe shaft 26 is held against downward movement by the cooperation of thebearing race 75 and snap ring 77 as described, the ultimate result ofthis arrangement is that the impeller 30 is always maintained in theaccurately spaced relation with the wall 48 which is established by theadjusted position of the screw 33 in the bore 63. The clearance betweenthe impeller and the wall 48 is particularly important for maximumefliciency of the pump when an open impeller 30 is used, as is preferredin this type of pump, and the construction of the invention makes itpossible to adjust the impeller vane Within a few thousandths of an inchof wall 48.

The invention offers special advantages in the initial construction andassembly of the pump, particularly in its ease of compensation formanufacturing tolerances. Thus it will be apparent that the overallconstruction of the pump, including the cast housing 24), sheet metalbase 50 and shaft 26, provides a possibility of considerable variationsin dimensions. With the use of the invention, however, these parts needbe manufactured only within relatively wide tolerances, since when thepump is assembled, the final adjustment of the impeller to the desiredaccurately spaced relation with the wall 48 is quickly and easilyaccomplished by application of a screw driver to the screw 33. Sincethis screw is effectively self-locking, by the provision of the plasticwedge 66, the impeller will hold its adjusted position for a normaloperating life without the necessity of subsequent adjustment. At thesame time, pumps of the illustrated type. are often required to handlerelatively abrasive liquids, and if the impeller should be worn in useto a point where there is too great a clearance between it and the wall48, it can easily be adjusted in the field with no tool other than ascrew driver. Thus the invention provides advantages for maintenancepurposes as Well as in the initial construction and assembly of thepump.

While the form of apparatus herein described on stitutes a preferredembodiment of the invention, it is to be understood that this inventionis not limited to this precise form of apparatus and that changes may bemade therein without departing from the scope of the invention which isdefined in the appended claims.

What is claimed is:

1. A centrifugal pump adapted to be adjusted after assembly or after anextended period of service to provide optimum pumping efiiciency and forsubstantially reducing dimensional tolerances during construction of thepump components, comprising a housing defining a pumping chamber, wallmeans substantially closing said chamber and having an inlettherethrough to said chamber, a drive shaft rotatably supported in saidhousing and with an end portion thereof projecting into said pumpingchamber from the side opposite said wall, a centrifugal open impellersplined for relative axial movement on said end portion of said shaftWithin said chamber and having a plurality of vanes extending therefromtoward said wall, means spaced between said housing and said impellerfor exerting a biasing force urging said impeller axially on said shafttoward said wall, thrust means connected to said end portion of saidshaft for opposing the axial movement of said impeller on said shaft,and means accessible through said inlet for axially adjusting saidthrust means in relation to said shaft to position said vanes of saidimpeller precisely in spaced relationship with said wall for optimumpumping efliciency.

2. A centrifugal pump adapted to be adjusted after assembly or after anextended period of service to provide optimum pumping efliciency and forsubstantially reducing dimensional tolerances during construction of thepump components, comprising a housing defining a pumping chamber, wallmeans substantially closing said chamber and having an inlettherethrough to said chamber, a drive shaft rotatably supported in saidhousing and with an end portion thereof projecting into said pumpingchamber from the side opposite said wall, a centrifugal open impellersplined for relative axial movement on said end portion of said shaftwithin said chamber and having a plurality of vanes extending therefromtoward said wall, a rotary mechanical seal assembly spaced between saidimpeller and said housing and arranged to form a running seal betweensaid shaft and said housing, spring means arranged to exert a biasingforce urging said impeller axially on said shaft toward said wall,thrust means connected to said end portion of said shaft for opposingthe axial movement of said impeller on said shaft, and means accessiblethrough said inlet for axially adjusting said thrust means in relationto said shaft to position said vanes of said impeller precisely inspaced relationship with said wall for Optimum pumping efliciency.

3. A centrifugal pump adapted to be adjusted after assembly or after anextended period of service to provide optimum pumping efficiency and forsubstantially reducing dimensional tolerances during construction of thepump components, comprising a housing defining a pumping chamber,rwallmeans substantially closing said chamber and having means defining aninlet therethrough to said chamber, a drive shaft rotatably supported insaid housing and with an end portion thereof projecting into saidpumping chamber from the side opposite said wall, means defining athreaded hole extending axially into said end portion of said shaft, acentrifugal impeller splined for relative axial movement on said endportion of said shaft within said chamber and having a plurality ofvanes extending therefrom toward said wall, a rotary mechanical sealassembly spaced between said impeller and said housing and arranged toform a running seal between said shaft and said housing, said sealassembly including spring means arranged to exert a biasing force urgingsaid impeller axially on said shaft toward said wall, a screw engagingin said threaded hole, thrust means associated with said screw foropposing the axial movement of said impeller on said shaft, and saidscrew including head means accessible through said inlet for axiallyadjusting said thrust means in relation to said shaft to position saidvanes of said impeller precisely in spaced relationship with said wallfor optimum pumping efiiciency.

4. A pump as defined in claim 3 wherein said screw is self-locking andincludes deformable plastic means engaging the inner surface of saidthreaded hole to provide for simple axial adjustment of said impellerWhile assuring that the adjusted position of said impeller in relationto said shaft will remain fixed during operation of the pump.

References Cited by the Examiner UNITED STATES PATENTS 2,669,938 2/54 LaBour 103-111 2,842,063 7/58 Kishline 61:211. 103 103 2,853,020 9/58Hollinger et a1. 103-111 5 1/63 Spring 103-111 5/63 Culleton 103103 5/63Danis 103111 5/64 Jennings 103-111 10/64 Van Blarcom 103103 FOREIGNPATENTS 8/60 Canada. 10/58 Italy.

DONLEY J. STOCKING, Primary Examiner. HENRY F. RADUAZO, Examiner.

1. A CENTRIFUGAL PUMP ADAPTED TO BE ADJUSTED AFTER ASSEMBLY OF AFTER ANDEXTENDED PERIOD OF SERVICE TO PROVIDE OPTIMUM PUMPING EFFICIENCY AND FORSUBSTANTIALLY REDUCING DIMENSIONAL TOLERANCES DURING CONSTRUCTION OF THEPUMP COMPONENTS COMPRISING A HOUSING DEFINING A PUMPING CHAMBER, WALLMEANS SUBSTANTIALLY CLOSING SAID CHAMBER AND HAVING AN INLETTHERETHROUGH TO SAID CHAMBER, A DRIVE SHAFT ROTATABLY SUPPORTED IN SAIDHOUSING AND WITH AN END PORTION THEREOF PROJECTING INTO SAID PUMPINGCHAMBER FROM THE SIDE OPPOSITE SAID WALL, A CENTRIFUGAL OPEN IMPELLERSPLINED FOR RELATIVE AXIAL MOVEMENT ON SAID END PORTION OF SAID SHAFTWITHIN SAID CHAMBER AND HAVING A PLURALITY OF VANES EXTENDING THEREFROMTOWARD SAID WALL, MEANS SPACED BETWEEN SAID HOUSING AND SAID IMPELLERFOR EXERTING A BIASING FORCE URGING SAID IMPELLER